The intracellular accumulation of methyl-beta-D-galactoside (MeGal) by the MeGal transport system of Escherichia coli is dependent on three genes, mgl A, B, and C, located in the 40-min region of the chromosome. One of the gene products, the galactose-binding protein, has been identified. Previous results show that MeGal translocation requires only two of the genes, mgl A and mgl C and that the presence of the galactose-binding protein increases the affinity of the system. The objectives in this project are: a) to establish the parameters of the transport activity dependent only on mgl A and mgl C; b) comparison of the mgl A,C dependent transport with that requiring all three genes in order to determine the role of the galactose-binding protein; c) identification of the gene products of mgl A and C.